<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.center-box {
				position: absolute;
				left: 50%;
				top: 50%;
				width: 800px;
				height: 600px;
				line-height: 600px;
				background-color: yellow;
				text-align: center;
				transform: translate(-50%, -50%);
			}
		</style>
	</head>
	<body>
		<div class="center-box">
			我是一个div1
		</div>
	</body>
</html>
